MCL injury swelling: what it can mean

MCL injury swelling is often felt around the inner knee, with tenderness or bruising near the ligament. Swelling can also come from irritation inside the joint or from another injured structure, so its location and timing do not establish the full diagnosis. Stiffness may make bending difficult, and a sense of looseness can point to reduced ligament support. A physical examination helps distinguish these patterns and decide whether imaging is useful.

Pause running, jumping and sideways movements while the knee is swollen. Elevate the leg when resting and use a cool pack wrapped in cloth for short periods if that feels helpful; protect the skin and avoid extreme cold. Do not force a stiff knee through pain. A clinician may recommend [Knee Bracing](/treatments/non-surgical-orthopedics/knee-bracing/) for support. Once movement is safe, [Physiotherapy](/treatments/physiotherapy-and-rehabilitation/physiotherapy/) can guide mobility and strengthening.

Have the knee assessed when swelling follows a clear injury, keeps returning, or is paired with locking or giving way. Get urgent help for severe swelling that develops quickly, a deformed joint, inability to bear weight, fever with a hot red knee, or numbness and unusual coldness in the foot.

Ask whether the swelling is outside the joint or within it, whether the MCL feels stable, and whether another ligament or cartilage structure may be involved. Ask how to monitor swelling during exercises and when a [Return-to-Sport Programme](/treatments/physiotherapy-and-rehabilitation/return-to-sport-programme/) is suitable.